A metal-free radical technique for cross-linking of polymethylhydrosiloxane or polymethylvinylsiloxane using AIBN

Bilayer Interphase for Air-Stable and Dendrite-Free Lithium Metal Anode Cycling in Carbonate Electrolytes

The intrinsic reactivity of lithium (Li) toward ambient air, combined with insufficient cycling stability in conventional electrolytes, hinders the practical adoption of Li metal anodes in rechargeable batteries. Here, a bilayer interphase for Li metal is introduced to address both its susceptibility to corrosion in ambient air and its deterioration during cycling in carbonate electrolytes. Initially, the Li metal anode is coated with a conformal bottom layer of polysiloxane bearing methacrylate, followed by further grafting with poly(vinyl ethylene carbonate) (PVEC) to enhance anti-corrosion capability and electrochemical stability. In contrast to single-layer applications of polysiloxane or PVEC, the bilayer design offers a highly uniform coating that effectively resists humid air and prevents dendritic Li growth. Consequently, it demonstrates stable plating/stripping behavior with only a marginal increase in overpotential over 200 cycles in carbonate electrolytes, even after exposure to ambient air with 46% relative humidity. The design concept paves the way for scalable production of high-voltage, long-cycling Li metal batteries.

Radical chemistry in polymer science: an overview and recent advances

Radical chemistry is one of the most important methods used in modern polymer science and industry. Over the past century, new knowledge on radical chemistry has both promoted and been generated from the emergence of polymer synthesis and modification techniques. In this review, we discuss radical chemistry in polymer science from four interconnected aspects. We begin with radical polymerization, the most employed technique for industrial production of polymeric materials, and other polymer synthesis involving a radical process. Post-polymerization modification, including polymer crosslinking and polymer surface modification, is the key process that introduces functionality and practicality to polymeric materials. Radical depolymerization, an efficient approach to destroy polymers, finds applications in two distinct fields, semiconductor industry and environmental protection. Polymer chemistry has largely diverged from organic chemistry with the fine division of modern science but polymer chemists constantly acquire new inspirations from organic chemists. Dialogues on radical chemistry between the two communities will deepen the understanding of the two fields and benefit the humanity.

Hydrophobic and thermal-insulating aerogels based on rigid cellulose nanocrystal and elastic rubber

Inspired from the ancient China philosophy of "coupling hardness with softness", we attempted the combination of rigid cellulose nanocrystals (CNC) and elastic rubbers to solve the limitations of structural brittleness and water sensitivity of CNC-based aerogels. Three rubber chains with the different chemical structures (silicon rubber, 1,2-polybutadiene, styreneic block copolymer) were covalently bonded on the CNC porous skeleton based on thiol-ene click chemistry, to fabricate the CNC/rubber composite aerogels. With the introduction of moderate loading levels of rubber, the composites aerogels exhibited low density and shrinkage, high porosity and specific surface area and improved mechanical performance. Furthermore, the presence of rubber components completely changed the hydrophilic nature of cellulose skeleton as the hydrophobic aerogels, contributing the superior solvents resistance and self-cleaning property. With their advantages on mechanical stability, heat insulation and hydrophobicity, the fabricated aerogels in this study exhibited the high added values in various potential applications.

Porous Materials Based on Poly(methylvinylsiloxane) Cross-Linked with 1,3,5,7-Tetramethylcyclotetrasiloxane in High Internal Phase Emulsion as Precursors to Si-C-O and Si-C-O/Pd Ceramics

Polysiloxane networks were prepared by hydrosilylation of poly(methylvinylsiloxane) (V₃ polymer) with 1,3,5,7-tetramethylcyclotetrasiloxane (D₄^H) at various Si-Vinyl: Si-H groups molar ratios in water-in-oil high internal phase emulsion (HIPE). Curing the emulsions followed by removal of water led to foamed cross-linked polysiloxane systems differing in the cross-linking degrees, as well as residual Si-H and Si-Vinyl group concentrations. Treatment of thus obtained materials in Pd(OAc)₂ solution in tetrahydrofuran resulted in the formation of porous palladium/polymer nanocomposites with different Pd contents (1.09–1.70 wt %). Conducted investigations showed that pyrolysis of the studied materials at 1000 °C in argon atmosphere leads to porous Si-C-O and Si-C-O/Pd ceramics containing amorphous carbon and graphitic phases. Thermogravimetric (TG) analysis of the starting cross-linked polymer materials and those containing Pd nanoparticles revealed that the presence of palladium deteriorates thermal stability and decreases ceramic yields of preceramic networks. The extent of this effect depends on polymer cross-linking density in the system.